Introduction Chemxin molecular sieve type 5a is an alkali alumino silicate; it is the calcium form of the type a crystal structure. Type 5a has an effective pore opening of 5 angstroms (0.5 nm). It will adsorb molecules with a kinetic diameter of less than 5 angstrom and exclude those larger. It is especially suitable for psa adsorber applications where it may be used for the separation of normal- and iso- paraffins (c4 to c6 species), in psa hydrogen purification and in oxygen concentrators. Regeneration Chemxin molecular sieve type 5a can be regenerated by either heating in the case of thermal swing processes; or by lowering the pressure in the case of pressure swing processes. To remove moisture from a 5a molecular sieve, a temperature of 250-300°c is required. A properly regenerated molecular sieve can give moisture dew points below -100°c, or mercaptan or co2 levels below 2 ppm. The outlet concentrations on a pressure swing process will depend on the gas present, and on the conditions of the process. Size 5a - zeolites are available in beads of 1-2 mm(10x18 mesh), 2-3 mm(8x12 mesh), 2.5-5 mm(4x8 mesh) and as powder, and in pellet 1.6mm, 3.2mm. Attention To avoid damp and pre-adsorption of organic before running, or must to be reactivated.